BRPI1107045A2 - locking device designed to prevent access to the junction box of an electrical cubicle and electrical cubicle comprising such a device - Google Patents

Abstract

LOCKING DEVICE DESIGNED TO PREVENT ACCESS TO THE JUNCTION BOX OF AN ELECTRIC CUBE UNDERSTANDING SUCH DEVICE. The present invention relates to a locking device designed to prevent access to the junction box of an electrical cubicle, said cubicle being connected on the line side to an electrical supply system and on the load side to at least one. cable, the cable or cables being housed in a junction box comprising a rear panel, a lower panel, an upper panel separating the junction box from the housing housing the switchboard assembly and the grounding means, two side panels And a door. This device is characterized in that it comprises a case (11) housing a lock (12) and a counter lever (13), said case (11) housing a lock (12) and a counter lever (13), said case (11) being designed to be fixed to the inner surface of a panel (21) of the junction box (3), said lock (12) collaborating on the one hand with the door (4) and on the other side, with a stem system (17) for door locking controlled by the shaft (7) of the grounding device (2), so that grounding command (2), so that cable grounding command (c) results on the door (4) being unlocked, said counter lever (13) cooperating on the one hand with the door (4) and on the other with a rod system (24) for locking the selector to prevent movement selector switch (8) to a position that allows the switchboard assembly to open and close when the door is not in the closed position.

Description

Report of the Invention Patent for "LOCKING DEVICE DESIGNED TO PREVENT ACCESS TO THE JUNCTION BOX OF AN ELECTRIC CUBICLE AND ELECTRIC CUBICLE UNDERSTANDING SUCH DEVICE".

The present invention relates to a locking device

designed to prevent access to the junction box of an electrical cubicle, said cubicle comprising at least one electrical distribution board assembly in series with cable grounding means, said cubicle being connected on the line side to a power and load side supply to at least one cable, the cable or cables being housed in a junction box comprising a rear panel, a lower panel, an upper panel separating the junction box from the housing housing the switchboard assembly and grounding means, two side panels and a door, said device comprising means for allowing the opening of the door mentioned above only if the grounding of the cables is effective, means for preventing closing switchgear assembly assembly as long as the door is not present and locked and means for reconnecting the grounding When the door is open but prevents closure of the switchboard assembly when said door is open, said cubicle comprising a selector manually connected to the switchboard assembly and the middle said selector being capable of being actuated by an operator and being movable between two positions, respectively, a position which allows operation of the opening and closing axis of the switchgear assembly and a position which does not allow this operation.

Two types of locking devices designed to prevent access to the junction box of a medium voltage electrical cubicle are known, these devices being able to be placed in these two categories depending on the location of the locking systems, the latter being capable of be located inside or outside the junction box.

In the case where the locking system is located outside the junction box, the principle is mechanical locking of the door from the outside. This device is often obtained by means of a latch added over the door and designed to move so that it is housed in a latch attached to the cubicle. The lock is then controlled directly or indirectly by the earthing device via a connecting rod system.

The main shortcoming of these systems lies in the fact that they are accessible from the outside and therefore liable to falsification or vandalism.

These systems therefore have to be oversized to support external equipment. In addition, they protrude from the cubicle, are difficult to integrate into the cubicle, and are generally anti-aesthetic.

In the case of the internal system to the junction box, the principle consists of mechanical locking of the door from the inside by means of removable locks located inside the junction box, said locks being controlled, directly and indirectly, by the grounding device. via a one-way connecting rod system.

The main shortcoming of these devices is that they penetrate the junction box and thus generate dielectric voltages.

The present invention solves these problems and proposes a device a locking device that is sufficiently compact not to generate dielectric voltages and robust enough to perform the locking function, as well as a medium voltage electrical cubicle comprising such a device. .

For this purpose, an object of the present invention is to provide a locking device of the type mentioned above, said device being characterized by the fact that it comprises a case housing a lock and a counter lever, said case being projected. to be fixed to the inner surface of a junction box panel, said lock cooperates on the one hand with the door and on the other with a door locking rod system controlled by the axis of the device grounding control results in the door being unlocked, said counter-lever cooperating on the one hand with the door and, on the other hand, with a lock selector locking rod system. to prevent movement of the selector to a position that permits opening or closing of the switchgear assembly when the door is not in the closed position.

According to a particular feature, the lock comprises a slidingly mounted elongate part, respectively, through two parts bent to form a case clamp, said elongate part comprising a first part about which a spring is fitted and a second part collaborating with the door locking rod system, said spring being fitted between one of the folded parts in a clamp and the second mentioned part above the elongated part, the spring conditioning the lock to a retracted position.

According to another feature, said second portion comprises an opening designed to cooperate with an angled portion formed at the end of the connecting rod called the second rod of the door locking rod system, that rod system moving through the opening. mentioned above against the spring return force in a direction substantially perpendicular to the lock movement direction, the spring conditioning the lock to a retracted position when the stem system moves away from the opening.

According to another feature, this counter lever is pivotally mounted with respect to the case and comprises a first end designed to cooperate with a sling provided on the door and a second end that collaborates with the selector lock rod system. .

According to another feature, the two stem systems mentioned above pass through the opening mentioned above.

According to another feature, said device comprising means for securing the door to the junction box, said means comprising securing means fixedly secured to the junction box or door, said securing means cooperating with at least one opening belonging to the door, respectively, to the junction box, to allow the door to slide relative to the junction box from a position in which said door is partially opposite the switchboard assembly and the box to a position in which said door is located completely in front of the junction box, a position that allows said door to be locked, fixing the door by first compressing the door against the junction box and then moving it down until it cooperates with the aforementioned fastening means, a position in which said door can be locked.

According to another feature, the above mentioned stem locking system for the door comprises a first stem comprising a first end fastened in rotation to the grounding shaft and a second end pivotally connected to one of the ends of a flat shank called a second 90 ° twisted shank, the other end of such a shank operates in conjunction with a lock, said shank being twisted so that said shank comprises two parts extending along two planes forming a substantially 90 ° between them, the foreground extending substantially perpendicular to the open / close axis of the switchboard assembly and the grounding axis and substantially parallel to the rear wall of the junction box and the background extending substantially parallel to the depth of the junction box and therefore to its side panels.

According to another feature, the selector locking rod system comprises a rod called the third rod linked with respect to a bracket called the first switchboard assembly bracket and comprising a first end collaborating with the selector and a second end mounted pivotably with respect to one end of a rod called the fourth rod 90 ° twisted so that said rod comprises two parts extending along two planes that form a substantially 90 ° angle therebetween. , the foreground extending substantially perpendicular to the open / close axis of the switchgear assembly and grounding axis and substantially parallel to the back wall of the junction box and the second plane extending substantially. parallel to the depth of the junction box and therefore to its side panels.

According to another feature, the first end of the stem called the third stem comprises a notch that cooperates with a cable belonging to the selector and extending substantially parallel to the opening and closing axis and the grounding axis.

According to another feature, in the so-called "missing door" position, the selector locking rod system is gravity moved to a selector locking position in which it cooperates with the above mentioned cable.

According to another feature, the so-called third rod is pivotally mounted on a bracket called the second bracket, said second bracket being riveted on said bracket above called the first bracket of the switchboard assembly.

According to another feature, the first stem of the door locking rod system is fixed to the grounding shaft by a clamp.

According to another feature, all parts of the locking device, that is, the case, lock, counter lever, door presence tab, door lock rod system and selector lock rod system, are made of sheet metal parts.

It is another object of the present invention to provide a medium voltage electric cubicle comprising a locking device comprising the above mentioned features taken alone or in combination.

But other advantages and features of the invention will become

more clearly evident in the following detailed description, which refers to

to the accompanying drawings provided for illustrative purposes only and in which:)

Figure 1 is a schematic representation illustrating a medium voltage electric cubicle according to the invention.

Figures 2 to 8 are partial perspective views illustrating a locking device according to the implemented invention.

in a medium voltage cubicle, respectively, in different positions of that device,

- Figure 2 represents the device mentioned above, the switch of the cubicle being closed, the grounding device being connected to the line and the door being closed and locked,

- Figure 3 represents the above mentioned device, the cubicle key being open, the grounding device being grounded and the door being closed and unlocked,

Figure 4 depicts the aforementioned device, the cubicle key being open, the grounding device being grounded and the door being closed and unlocked;

- Figure 5 represents the above mentioned device, the switch of the cubicle being open, the grounding device being grounded and the door being opened,

- Figure 6 represents the above mentioned device, the cubicle key being open, the grounding device being connected to the line and the door being open,

- Figure 7 represents the above mentioned device, the cubicle key being open, the grounding device being grounded and the door being opened,

- Figure 8 represents the above mentioned device, the switch of the cubicle being open, the grounding device being grounded and the door being closed,

- Figure 9 is a partial perspective view illustrating the attachment of a door presence indicator tab over the door,

Figure 10 is a partial perspective view illustrating the attachment of a case comprising the lock on the door;

- Figure 11 is a partial perspective view illustrating Figure 10.

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attaching the selector lock rod system and the door lock rod system to a

- Figure 12 is a perspective view illustrating separately the door's presence tab, the lock housing;

ί the door lock rod system and the selector lock rod system.

In Figure 1, a medium voltage electrical cubicle C can be seen electrically connected, on the line side, to a high voltage electrical power system R and, on the load side, to cables c, said cubicle comprising a set of electrical switchboard such as a circuit breaker or circuit breaker 1 connected in series with a grounding device 2, said switchboard assembly being connected on the line side to the grounding device, said device grounding connection being connected, on the load side, to said junction box 3, said door 4 being accessible by means of a door.

In Figures 2 to 8, the cubicle comprises, per se known, a support 5, called the first support, to which a pole axis 6 is rotatably adapted, via which the contacts of the assembly The switchgear can be closed or opened and an axis 7 belonging to the grounding device, said axis being capable of being operated by an operator between two positions, respectively, grounding the cables or connecting the cables to the line.

The cubicle also comprises a selector 8 mechanically connected to the control axis or pole axis, said selector being able to be moved to one of two positions, respectively, a first position in which the selector 8 allows the axis 6 is operated and a second position in which the selector prevents operation of that axis.

In a manner also known per se, cubicle C comprises a locking device comprising means for preventing access to the junction box, provided that cable grounding is not effectively carried out, means for preventing closure of the switchboard assembly. as long as the junction box port is not present 10

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and locked and means for allowing the earthing device to be reconnected to the line with the door open, but prevent closing of the circuit breaker or circuit breaker when that door is open.

According to the invention, the locking device according to the invention comprises three sets.

The first set comprises a locking device 9 of the selector 8 designed to be controlled by the door 4, the second set comprises a door locking device 10 designed to be controlled by the secondary axis of the grounding device and the third set comprises a housing 11 housing a lock 12 and a counter lever 13, said counter lever 13 being designed to cooperate with a tongue 14 provided on the door 4 designed to indicate the presence or absence of the door. The door presence indicator tab, the case and the two locking devices are successively represented from left to right in Figure 12.

As can also be seen from these Figures 2 to 8, the junction box door 4 is secured to the junction box by means of securing means comprising securing means 15 integral with the junction box, said securing means cooperating with a junction box. opening 16 provided in the door to allow the door to slide between a first position in which the door is partially opposite the switchboard assembly and in front of the junction box and a position in which the door is completely opposite the box joint and collaborate with the fixing means mentioned above. Fixing the door is thus performed by first compressing the door 4 against the junction box 3 and moving it downward until it cooperates with the fixing means 15 mentioned above, a position in which said door can be locked as explained below.

The door locking device 10 comprises a stem system, said stem system comprising a first stem 18 comprising a first end 18a rotatably fastened to the grounding axis 7 and a second end 18b connected thereto. an

20

In a hinged manner, at one end of a flat shank 19 called a second shank 90 ° twisted, the other end 19b of such shank being designed to cooperate with a lock 12, said shank 19 being twisted in such a manner. that rod comprises two parts 19c, 19d extending in two planes at a substantially 90 ° angle therebetween, the foreground extending substantially perpendicular to the opening / closing axis 6 of the frame assembly and grounding axis 7 and substantially parallel to the back wall 20 of the junction box and the background extending substantially parallel to the depth of the junction box and thus its side panels 21. The free end of the rod Twisted 19 comprises a bevelled portion 19c designed to cooperate with an opening 23 provided in lock 12 as will be explained below.

The shank system 24 locking the selector 8 comprises a shank called the third shank 25 hinged with respect to said carrier 5 of the switchboard assembly 1 and comprising a first end 25a collaborating with the selector 8 and a second pivot mounted end 25b with respect to one end 26a of a rod called fourth rod 26 90 ° twisted so that said rod comprises two portions 26c, 26d extending in two planes, forming an angle of substantially 90 ° between the same, the first plane extending substantially perpendicular to the open / close axis 6 of the switchboard assembly and grounding axis 7 and substantially parallel to the back wall 20 of the junction box and the second plane extending substantially parallel to the depth axis of the junction box and thus to its side panels 21.

The first end 25a of the so-called third rod comprises a notch 27 which cooperates with a cable 28 belonging to the selector 8 and extending substantially parallel to the opening axis 6 and the grounding axis 7, the selector being mounted with respect to rotation. to the support called first support 5 mentioned above between the two positions mentioned above. The free end of the stem called the fourth stem 26 cooperates with the aforementioned counter lever 13 adapted to the case 11, as explained below.

As can be particularly seen from Figure 11, the so-called third rod 25 of the door locking rod system 17 is pivotally mounted on a holder called second bracket 29 riveted over the so-called first bracket 5 mentioned above the assembly. while the first stem 18 of the door locking rod system 17 is secured to the grounding shaft 7 by a securing means 32.

The locking device according to the invention also comprises the aforementioned case 11 designed to be fixed to the inner surface of a junction box side panel 21 as shown in Figure 10. Said case houses a lock 12 and a counter lever 13. This latch 12 comprises a slidingly mounted elongate portion 30 via its two opposite ends respectively through two portions folded to form a clamp 11a, 11b of the case 11, said elongate portion comprising a first portion 30c around the which a spring 31 is adapted and a second part 30d cooperating with the door locking rod system 17, said spring 31 being adapted between one 11a of the bent parts to form a clamp and the second part 30d mentioned above the one. elongated portion 30, spring 31 conditioning lock 12 in a retracted position.

That second part 30d comprises an opening 23 designed to cooperate with an angled part 19e formed at the free end of the rod called the second rod 19 of the door locking rod system 17, that rod system moving through the opening mentioned above. against the spring return force in a direction substantially perpendicular to the direction of movement of the lock, the spring conditioning the lock to a retracted position when the stem system moves away from the opening.

The stem system 24 for locking the selector, the free end of the fourth stem 26, the quat collaborates with the counter lever 13, is also adapted through this opening 23.

The counter lever 13 is pivotably mounted with respect to the case 11 and comprises a first end designed to cooperate with a tongue forming part 14 fixed to the door as shown in Figure 9 and a second end collaborating with the door. rod system 24 for selector locking.

Operation of the locking device according to the invention will be described below with reference to the figures.

In Figure 2, pole axis 6 in the closed position, the position of selector 8 toward the left side of the switchboard assembly with respect to Figure 2 having allowed this movement and grounding device 2 is connected to the line. Selector cable 28 is released from the stem system notch 17 for door locking. Door 4 is in the locked and locked position, locking being performed by inserting the lock 12 into the opening 33 of door 4, against the force of the spring 31 which is compressed via one end 31a over the door. and via its opposite end 31b over the lock, this locking movement was caused by movement of the door locking rod system 17 through the opening 23, by cooperating with the angled shape 19e of the locking system with the opening mentioned above. In this position, the door locking tongue 14 conditions the counter lever 13 upwards, which has the actuation effect of the stem called the third stem 25 in a counterclockwise rotational motion. In this position, access to the junction box is prevented as long as cable grounding is not effective.

In Figure 3, the switch is open. Pole shaft 6 is in the open position which has set selector 8 to the grounded position.

In Figure 4, the switch is open and the secondary ground shaft 7 is in the grounded position. This caused upward movement of the second rod 19, releasing the last of the opening 23 mentioned above. This results in spring 31 conditioning lock 12 to a retracted position, allowing door 4 to open. In Figure 5, the door is open, which has the effect of releasing the counter lever 13 of the door's presence tab, which allows the stem system 24 to lock the selector to move it through the lock opening 23 due to the effect of gravity. This movement of the rod system 24 results in clockwise rotational movement of the third rod 25 and engagement of the notch 27 with the cable 28 of the selector 8, thereby preventing selector 8 operation. This position of the selector does not prevent - that the grounding spindle 7 is reconnected to the line, as is the case in Figure 6, for example when conducting cable injection tests. This reconnection to the line has the effect of moving the second rod 19 down through opening 23, which has the effect of causing the lock 12 to move out of the case 11. This results in being impossible to retract. adapt the door. Retrofitting port 4 requires re-grounding the earthing device to condition latch 12 to a retracted position as shown in Figure 7. This position allows reconnection of the earthing device to the line but does not allow closing of the earthing device. circuit breaker or circuit breaker 1. Retrofitting the door then causes counter lever 13 to rotate, which has the effect of causing upward movement of the fourth rod 26 and releasing cable 28 from notch 27, as illustrated in Figure 8. This release it still does not allow pole axis operation and, in particular, closure of the switchboard assembly, since c cables must first be reconnected to the line.

A locking device that provides total operator safety without penalizing ergonomics has therefore been obtained according to the invention.

The device according to the invention is thus robust and compact and can be easily integrated into the junction box via the front panel at any stage of life, but requires no adjustment and comprises a minimum of parts.

Dimensional constraints are overcome by a compact lock concept combined with a compact stem system. This compaction is achieved by 90 ° twisted flat rods, allowing their spatial occupancy to be optimized without changing the plane (in the depth direction, once control is considered and in the width direction, since the junction is considered). This extra-flat lock can be housed at flank thickness

of the junction box. This small footprint means there is no obstruction for users when performing junction box operations to adapt connectors, perform maintenance operations, cable testing, etc. The small footprint also makes it possible not to generate any dielectric voltage. Equipping the junction box with a locking device does not penalize its dielectric performances.

In addition, this subset is fully accessible from the front panel. Thus, it is very easy to equip a cubicle. This is particularly interesting in the case of juxtaposed wraps (cubicle assembly). It allows operations to be performed directly via the front of the part in question without disassembling adjacent elements.

Adaptation of the different elements is carried out simply and quickly by simply riveting and securing without any screws or pins, this operation requiring no adjustment by the operator. This system is still a positive security system. In the

When idle, the lock is in the "absent door" position, where it is impossible to operate the circuit breaker or circuit breaker. This state is naturally obtained by gravity. Likewise, the spring is for lock conditioning purposes only and thus for door release. In the event of a spring malfunction, the door therefore remains in the locked position. In addition, selector locking requires engagement, the more force applied to the selector, the more securely the system locks.

The whole of the locking system is obtained by mounting single-sheet metal parts. These parts are obtained by "traditional" folding and not

want any specific process or precise tolerance.

The lock is made of two sheet metal parts held solely together by a spring. These parts are assembled extremely easily and quickly without any tools.

Once the lock assembly has been fitted into a cubicle, there is no access possible. Any risk of damage is thus avoided.

All of this contributes to simple and fast deployment without any particular tools for a relatively low cost.

The invention applies to any compartment of an electrical cubicle comprising an operating shaft and a grounding shaft and having controlled access to operating parts via a door.

The invention, of course, is not limited to the described and illustrated embodiment, which has been provided for exemplary purposes only.

On the contrary, the invention extends to encompass all technical equivalents of the described means, as well as combinations thereof if the latter are embodied in the spirit of the invention.

Claims (14)

1. Locking device designed to prevent access to the junction box of an electrical cubicle, said cubicle comprising at least one electrical distribution board assembly in series with cable grounding means, said cubicle being connected on the line side to a power supply system and on the load side to at least one cable, the cable or cables being housed in a junction box comprising a rear panel, a lower panel, an upper panel separating the junction box from the housing houses the switchboard assembly and grounding means, two side panels and a door, said device comprising means for allowing the opening of the door mentioned above only if the grounding of the cables is effective, means for preventing the closing of the door. switchboard assembly as long as the door is not present and locked and means to allow reconnection of the means of grounding the line when the door is open but preventing closure of the switchboard assembly when said door is open, said cubicle comprising a selector manually connected to the switchboard assembly and in the grounding means, said selector being capable of being operated by an operator and being movable between two positions, respectively, a position allowing operation of the opening and closing axis of the switchboard assembly and a position not allowing such operation characterized in that it comprises a case (11) housing a lock (12) and a counter lever (13), said case (11) being designed to be fixed to the inner surface of a panel (21) of the housing junction (3), said lock (12) cooperating with the door (4) on the one hand and, on the other hand, with a shaft controlled door locking system (17) (7) of the grounding device (2), so that the grounding control of the cables (c) results in the door (4) being unlocked, said counter lever (13) collaborating on the one hand with the door (4) and on the other on the other hand, with a rod system (24) for locking the selector to prevent movement of the selector (8) to a position that allows opening and closing of the switchboard assembly (1) when the door is not in the closed position. . Locking device according to claim 1, characterized in that the lock (12) comprises an elongated part (30) slidingly mounted, respectively, through two folded parts in a clamp (11a, 11b) of the case ( 11), said elongated part (30) comprising a first part (30c) about which a spring (31) is fitted and a second part (30d) which cooperates with the door locking system (10), said spring (31) being fitted between one (11a) of the folded parts in a clamp and the second part (30d) mentioned above the elongated part (30), the spring (31) conditioning the lock (12) to a retracted position. Locking device according to claim 2, characterized in that said second part (30d) comprises an opening (23) designed to cooperate with an angled part (19e) formed at the free end of the rod called the second one. stem (19) of the stem locking system (17) for door locking, this stem system moves through the opening (23) mentioned above against the spring conditioning force (31) in a substantially direction perpendicular to the direction of movement of the lock (12), the spring conditioning the lock to a retracted position when the stem system (17) moves away from the opening. Locking device according to any one of claims 1 to 3, characterized in that the counter lever (13) is hinged with respect to the case (11) and comprises a first end (13a) designed to cooperate with a locking device. tongue (14) provided over the door and a second end (13b) which cooperates with the stem system (24) for locking the selector. Locking device according to claim 3 or 4, characterized in that the two stem systems (17, 24) mentioned above pass through the opening (23) mentioned above. Locking device according to any one of claims 1 to 5, characterized in that it comprises means for securing the door (4) over the junction box (3), said means comprising securing means (15). ) integral with the junction box (3) or the door (4), said fixing means (15) cooperating with at least one opening (16) belonging to the door, respectively, to the junction box, in order to allow sliding of the door with respect to the junction box from a position in which said door is partially opposite the distribution frame assembly (1) and the junction box (3) to a position in which said door is fully opposite to the junction box, a position permitting locking of said door, fixing the door being carried out by first compressing the door against the junction box (3) and then moving it downward until it cooperates with the door. fixing means (15) mentions above, a position in which said door (4) can be locked. Locking device according to any one of the preceding claims, characterized in that the aforementioned stem system (17) for locking the door comprises a first rod (18) comprising a first end (18a) attached to it. , in rotation, to the grounding shaft (7) and a second end (18b) hingedly connected to one (19a) of the ends of a flat rod called a second rod (19) twisted 90 °, the other end (19b) ) of such a rod operates in conjunction with a lock (12), said rod (19) being twisted so that said rod comprises two parts (19c, 19d) extending along two planes forming a substantial angle. 90 ° between them, the foreground extending substantially perpendicular to the opening / closing axis of the switchboard assembly (1) and the grounding axis (7) and substantially parallel to the rear wall (20). ) of junction box and the background extending substantially parallel to the depth of the junction box (3) and thus to its side panels (21). Locking device according to any one of the preceding claims, characterized in that the selector locking rod (24) comprises a rod called a third rod (25) hinged with respect to a support called first bracket (5) of the switchboard assembly and comprising a first end (25a) cooperating with the selector (8) and a second pivot mounted end (25b) with respect to one (26a) of the ends of a rod called a fourth rod (26) twisted 90 °, such that this rod comprises two parts (26c, 26d) extending along two planes, forming a substantially 90 ° angle therebetween, the first plane extending substantially substantially perpendicular to the distribution frame assembly opening / closing axis and grounding axis (7) and substantially parallel to the back wall (20) of the junction box and the background extending substantially parallel to the depth of the junction box and thus to its side panels (21). Locking device according to claim 8, characterized in that the first end (25a) of the stem called the third stem (25) comprises a notch (27) which cooperates with a cable (28) belonging to the selector. (8) and extending substantially parallel to the opening and closing axis (6) and the grounding axis (7). Locking device according to claim 9, characterized in that, in the so-called "missing door" position, the selector locking rod (24) is moved by gravity to a selector locking position in which he collaborates with the cable (28) mentioned above. Locking device according to any one of claims 8 to 10, characterized in that the rod known as the third rod (25) is hingedly mounted on a bracket called the second bracket (29), said second bracket (29). ) being riveted over the so-called first bracket (5) mentioned above the switchboard assembly (1). Locking device according to any one of the preceding claims, characterized in that the first stem (18) of the door locking stem system (17) is fixed to the grounding axis 5/5 (7) by a clamp (32). Locking device according to one of the preceding claims, characterized in that all parts of the locking device, that is, the case (11), lock (12), counter-lever (13), tongue of the door (14), stem system (17) for locking the door and stem system (24) for locking the selector (8) are made of single sheet metal parts. Medium voltage electrical cubicle comprising a locking device according to any one of the preceding claims.